So this suggestion is based on 4 volt white LEDs. The circuit would work best as a hybrid of the two circuits, with groups of 7 LEDs in series with a current limiting resistor, all across 24 volts. The resistor value must be set to limit the current to the selected value, probably 50 milliamps.

1) Nobody sells 4V white LEDs. They have a range of voltage from about 3.0V to about 4.0V. You get whatever they have.
3V ones would burn out and 4V ones will not light up. Most ordinary LEDs are used at 20mA and the absolute max current is 30mA. 50mA is way too high.
Use 24V if you must and 5 LEDs in series and at an average of 20mA. A 1/4W resistor will be warm but not too hot.

 

1) Nobody sells 4V white LEDs. They have a range of voltage from about 3.0V to about 4.0V. You get whatever they have.
3V ones would burn out and 4V ones will not light up. Most ordinary LEDs are used at 20mA and the absolute max current is 30mA. 50mA is way too high.
Use 24V if you must and 5 LEDs in series and at an average of 20mA. A 1/4W resistor will be warm but not too hot.

I suggest examining the specification sheets for recent illumination type LED devices. 20 mA is the standard for indicator type LEDs.

 

I suggest examining the specification sheets for recent illumination type LED devices. 20 mA is the standard for indicator type LEDs.

Sorry, MisterBill2 but he said he is using blue LEDs for decoration and shows a 150 ohm current-limiting resistor with 3V across it (20mA). The LED ceiling light in my computer room has 72 surface mounted white LEDs that are so bright (100mA each) that they are blinding.

 

OK, somehow I missed that part about decorative blue LEDS. My comment is that illumination LEDs run at much higher currents.